The present invention relates to cooling towers. More particularly, the present invention relates to direct or open-type cooling towers. Cooling towers rely on evaporation to remove heat from a stream of water (or other medium). In open cooling towers, the water to be cooled is exposed directly to the atmosphere. Typically, the warm water is sprayed over the top of a “fill” portion in the cooling tower while ambient air is blown through the fill. The fill is used to increase the contact area between the warm water and the (cooling) air, thereby providing greater heat transfer.
One problem associated with cooling towers is the build up of scale deposits on the fill (i.e. fouling). Minerals dissolved in the cooling water accumulate on the fill as the water evaporates. Buildup or fouling can significantly reduce the heat transfer and, therefore, reduce the efficiency of the cooling tower. Further, excessive fouling can even cause the fill portion to collapse due to the additional weight of the fouling material. It is therefore desirable to monitor the amount of fouling or buildup that occurs on the fill.